1. Field of the Invention
The present invention relates to a semiconductor device provided with a wire that electrically connects a printed wiring board and a semiconductor chip, and a method for manufacturing the semiconductor device.
2. Description of Related Art
Various types of semiconductor devices are currently being manufactured. A semiconductor device includes a semiconductor chip and a printed wiring board. The semiconductor chip is mounted on a printed wiring board. The semiconductor chip is electrically connected to pad formed on the printed wiring board.
As one such semiconductor device, there is a device in which a semiconductor chip and a printed wiring board are electrically connected via wires. The wires are connected to electrode pads on the semiconductor chip and connection pads on the printed wiring board. JP2001-024024A, JP2008-251929A and JP11-135539A disclose semiconductor devices in which electrode pads in the center of one surface of the semiconductor chip are provided.
When the electrode pads are formed in the center of the semiconductor chip, the wires extend from the center of the semiconductor chip, passing through the vicinity of the edge of the semiconductor chip to the connection pads of the printed wiring board. When the conductive wires are long in this way, the loop of the conductive wires becomes high. As a result, there is a problem that it is difficult to make the semiconductor device thinner. There is also a problem in which the flow of sealing resin that seals the semiconductor chip causes a wire sweep, and a short circuit is likely to occur in the wire.
In order to solve these problems, the semiconductor device described in JP11-135539A includes a lower polyimide tape pasted to the semiconductor chip and a wire that contacts the lower polyimide tape. An upper polyimide tape is pasted to the lower polyimide tape. The wire is sandwiched between both polyimide tapes and is fixed by both polyimide tapes.
According to JP11-135539A, after the printed wiring board and the semiconductor chip are connected via the wire, the wire is strongly pressed by the upper polyimide tape. For this reason, the wire may be deformed. When the wire is deformed, there is a possibility that a short circuit may occur between wires or between the wire and the semiconductor chip.
Furthermore, there is also another problem in which a cavity may be formed between the two polyimide tapes. In this case, the fixing of the wire may become insufficient. Furthermore, since the two polyimide tapes to which an adhesive is applied are superimposed one upon the other, there is another problem in which the total thickness of the two polyimide tapes increases and the thickness of the semiconductor device increases.
Therefore, it is desired that an improved semiconductor device and a method for manufacturing such a semiconductor device be provided.